I am having trouble with my batteries. I plan to buy a new one, but I want to be sure in the future I know the condition of both of them. I have a voltmeter I would like to install, and I want to set up a switch so I can read the volts on each batter. Can I just run a line from each one to an a-b type switch or is there more to it? Also I am not sure my motor is charging the batteries. Can I use a volt meter to test output from the engine while it is running somehow. thanks for the input.